Sometimes, we give a correct answer to a question, and then later, the OP changes the question, so that the answer does not match the question any more. Later, some careless readers come in and vote down those answers that used to be correct but do not match the question any more because the question was edited. We cannot keep "polling" all the questions that we have ever answered to see if they are changed. What is the best way to deal with these stupid down votes?
It is not the down votes that are stupid; the question being changed is the problem.
In such a case, one thing should happen: the question needs to be reverted, if it was truly altered significantly.
If you can't or don't want to do it, or if you already have and the OP edits it back, flag the question as "Other" and describe the problem. We'll take care of it.